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@gn-itch tant datent @fitta IMPROVEMENT IN EXPNDING MANDRELS.

@the Srigshnle aferra tu im that @am rtmtarl mating mi nf tige same.

TO ALL WHOM IT MAY CONCERN:

Be it known that I, JAMES BUCKLEY MALLALIEU, of' Chicago, in the Stateot" Illinois, have-invented a new and improved Mandrel, as a mechanicalinstrument or tool for use in turning iron, brass, or metals, or wood inturning-lathes; and I do declare that the following is a full and exactdescription thereof, reference bei-ng had to the accompanying drawings,andto the letters of reference thereon.

Figure 1 is a top View of the mandrel.

Figure 2 is a top view of the bush or jacket.

Figure 3 is a section view of the bush or jacket in a line through thecentre.

Figure 4 is an end view oi' thebush `or jacket.

Figure 5 is a top view of the mandrel, with the bush or jacket tted tothe same.

Figure 6 is the improved mandrel tted intofa base to be turned.

Similar letters, where they occur in different figures, denote the sameparts.

The nature and object of my inventionare to construct a taperingmandrel, provided with an elastic or yielding hush or jacket, which willenable me to use the same mandrel and bush or jacket .for differentpieces of work, and at the same time will enable me to turn the ends ofthe work I am engaged on, or rim it out, as circumstances shouldrequire. I use a mandrel tapering in form to such a degree ascircumstances should require, and on this mandrel I use a bush orjacket, with the bore made to conform to the mandrel, and the periphery`made with parallel sides. At one line on the surface of this lbushorvjacket is cut a slit longitudinally through to the bore, thus makingthe bush or jacket yielding, which will enable itfto iit at any point onthe tapering mandrel desired. This bush or jacket, when in use, is madeflush with or yshorter than the bore of the article to be turned, bothsides or ends ofthe article extending each way beyond the bush orjacket. It is obvious that this construction ofthe bush or jacket willenable me, while holding the bushtightly iu the bore aforesaid, to turnthe article I am working on both ends perfectly, Without danger ofinjuring the mandrel or bush by the turning-tool, and yWithout thenecessity of a collar to hold the bush from slipping through, andwithout reversing the article to be turned on the mandrel for finishing;but will also enable me to rim out the article as I mightv desire.

I ama-ware that yielding bushes or jackets on tapering mandrels havebeen used before. One 1s shown in the patent `granted vto Sherrod, June21, 1853. But this construction fails to produce the advantageousresults before described, which are only attained by my peculiararrangement. n

To enable others skilled in the art to make and use my invention, I willproceed to describe the same with reference to the drawings annexed. I

A is a mandrel of cast steel, or other suitable metal, hardened at theends to the depth of from one-eighth to one-fourth of an inch. It may beof any suitable dimensions and length, with an inch diameter at thelargest end, and seven inches in length; it may taper about one-eighthof an inch, so that the diameter of the smallest end shall beseven-eighths of an inch, and in about that proportion or angle for alonger or shorter mandrel. a a are sockets in the two ends of themandrel,'sunk at an angle of about eighty degrees, ending in a-smallerand nearly perpendicular socket, which sockets are to be hardened,.andare for the hold of the centres when placedin the turning-lathe ormachine. b b are two shoulders at each end of the mandrel, flattened onone side at c c, through which, by means ot' a dog or other similarinstrument rightly adjusted, the motion of the mandrel upon the centresmay-be promoted. B is the bush or jacket, of cast i'ron 0r othersuitable metal, with a cut, slit, or opening, d, throughA its entirelength. It is to be made with a taper in its interior circle,corresponding with the taper of the mandrel, to which it is to be tted,and its exterior surface, periphery, or disk ofl equal diametersthroughout, and of parallel lines or surfaces, and it may be of anylength or thickness of metal desired and convenient for-the purposesaforesaid.4 Upona mandrel of the length and dimensions above described,thebush orja'cket may be two inches in length and one-eighth of an inchin thickness of metal. It will be Obvious, however, that in constructingand operating my improved mandrel, the length and diameter of themandrel, and the length and thickness of metal of the bush or jacketrequired, must vary according 13o-'the size and thickness and consequentweight ofthe articles to be turned, and the power used in operating themachine. D is a column base to be turned, shown for illustration.

The' operation 'of my invention is shown by placin'g the bush or jacketB on the mandrel A, and fitting the complete tool into the base D to beturned, as in iig. 6. The whole is then placed on the centre points z a,into the usual turning-machine or lathe, and by the power appliedsubjected tothe action of :L Common turningchisel, with the results andadvantages before enumerated.

W'ha-t I claim as my invention, and `desire to secure by Letters Extent,is-

The eombinationof the mandrel A With the movable bush or jacket B,Without a collar, as and for the puriposes set-forth. f

JAMES B. MALLALIEU.

lVitnesses:

S. A, GOODWIN, GEO. E. ADAMS.

